The liquid crystal display is an image display wherein electrooptical properties of liquid crystal molecules are used to display characters or images. However, the liquid crystal display makes use of liquid crystal molecules having optical anisotropy; thus, good display characteristics are exhibited in a certain direction while its screen becomes dark or unclear in other directions. For this reason, the liquid crystal display is equipped with a birefringent film having a predetermined retardation. For reference, a birefringent film is also called a retardation film, a compensation layer, or some other.
Hitherto, a birefringent film has been known which contains, as a main component thereof, an aromatic polyester (Patent Document 1).
The aromatic polyester described in Patent Document 1 has a repeating unit in which terephthalate or isophthalate is ester-linked to bisphenol groups.
This aromatic polyester-containing birefringent film is usually formed by a solution casting method.
The solution casting method is a method of dissolving a polymer in a solvent to prepare a solution, coating this solution onto a metallic drum, a substrate or the like, and then drying the workpiece to form a film.
Patent Document 1: JP-A-2004-70329